Amazing Sunset and Sunrise Colors

Every sunrise and sunset provides a wide range of visual effects, ranging from the elongation of the disk of the Sun as it hugs the horizon, to the amazing range of colors you see in the minutes before and after the Sun’s passage through the horizon. One of my favorite effects is the curious coloration of the opposite horizon from the sunrise or sunset where one sees a colorful and rapidly changing band of sky called the Belt of Venus.

Belt of Venus at 35,000 Feet

Despite the name, the effect does not have anything to do with Venus the planet. Rather, the effect is due entirely to the shadow cast by the Earth into space, and our perception of that shadow as we observe the horizon from our vantage point along the Earth’s terminator. As we gradually rotate out of the darkness of night (at sunrise) or into the darkness (at sunset), we have a short-term view into the shadow of Earth which occupies the opposite horizon from the Sun. The colors are quite vivid with dark blue low along the horizon, and the refracted colors of the sunrise or sunset above that, creating a layered effect of blue and pink.

Belt of Venus on SF Bay

The images to the left and right show two interesting views I had of the Belt of Venus over the past many months. The first one was taken from 35,000 feet above the United States where I had the very unique vantage point of looking sideways into the sunset belt from high altitude rather than seeing it from sea level. I still cannot figure out why there is a white glow below the belt itself. The second image was taken from the Exploratorium in San Francisco, looking east after sunset toward Treasure Island and the Bay Bridge. The colors and pattern on the horizon were to be expected, but the rays of dark and light blue extending up into the sky were not. Here in this situation, I still cannot figure out the atmospheric phenomenon that would cause such an unusual ray of dark blue to extend upward into the sky. But in both cases the interplay of color and light was indeed remarkable and although pictures from an iPhone camera cannot do justice to the magnificence of the real thing, it’s something I felt compelled to document and write about.

So next time you are watching an amazing sunrise or sunset, be sure to turn around and take in the drama on the other horizon, or you will have missed out on some of the most beautiful parts of the sky.

What's Up in Astronomy and Space Exploration

Last night a friend asked me "what's up in space exploration and astronomy in the coming weeks?" and I wrote down this list. Enjoy!

October 19 - Watching a comet from Mars with NASA

October 23 - Partial Eclipse of the Sun

October 25 - Bay Area Science Festival astronomy night

November 12 - Rosetta probe to land on a comet

November 17 - A meteor shower: the Leonids

The Next Blood Moon: October 8, 2014

Total Lunar Eclipse of October 8th

We're in for the second of four total lunar eclipses in 2014-2015. Next week the Full Moon slips into the shadow of the Earth and reveals itself as a 'blood moon' in the early morning sky of Wednesday October 8th. You'll need to be up in the wee hours of the night, as the eclipse reaches total phase at 3:25 am pacific time, where it will remain in total eclipse for an hour. Given our good weather in San Francisco, this should be nicely on display and the view from the west coast should be nice, if you can get out to the beach. The Moon itself will not be a 'super moon' but will be larger than most Full Moons, so it should be an awesome sight.

You can find more details on the Sky & Telescope website. You'll need clear skies and a good view of the sky to the southwest. It should be a dramatic blood-red color, as the Moon will move deep into the umbral shadow of the Earth.

This infographic from Guy-André Pierre-Nicolas of astroshop.eu is an excellent resource that illustrates beautifully many facets of a lunar eclipse.

Image courtesy of Sky & Telescope.

Red 'Stars' and White Moon

Slender Moon, Mars and more

For the next week, the twilight sky will feature a close alignment of two bright shiny red objects, Mars and Antares, and the slender Moon wending its way through the southwestern sky. The Moon encounters the ringed planet Saturn on Saturday 27th and then brackets the close pairing of orange-red Mars and the red supergiant star Antares in the constellation Scorpius. This first lunar cycle of autumn should start out beautifully with the waxing Moon and some lovely alignments. Look south and west shortly after sunset each evening for the best viewing.

Image courtesy Sky & Telescope.

Luxury Star Gazing

Ritz Carlton Half Moon Bay

Fall in the San Francisco Bay Area means clear skies and mild temperatures, and clear skies along the coast - a welcome change after the fog of summer. If you are in the Bay Area in the coming months, stop by the Ritz Carlton Hotel and Resort in Half Moon Bay for a Friday night star party. I am running star parties there a couple Fridays per month and love the setting, the reasonably dark skies, and the fun interaction with guests from all around the world. The patio is located on a stunningly beautiful stretch of California coast next to the 18th green of the Ocean Course. Hope you can make it. Click here for the schedule and more information.

Celebrate the Moon - Saturday September 6th

This Saturday is International Observe The Moon Night. Where will you be for this special evening? I'll be conducting sidewalk astronomy in front of the Exploratorium in San Francisco along with other astronomy enthusiasts. The Moon will be a few days away from another Supermoon, and if the skies cooperate, we should have a lovely view of Earth's natural satellite in gibbous phase between first quarter and full. Click the link for more information on International Observe The Moon Night. Hope to see you at an event.

KFOG Broadcast - August 12, 2014

I paid a visit to the KFOG Morning Show and had a fun chat with Renee about the Supermoon, Perseid Meteor Shower, How to Look At The Night Sky, and Star Parties in and around San Francisco. Click here to listen. 

Jupiter & Venus Conjunction – Closest Approach Since 2000

After the Moon, the two brightest objects in the night sky are the planets Venus and Jupiter. Venus is a close neighbor and a very reflective planet, dominating morning and evening skies with its brilliant white shimmer against the changing colors of the dawn or dusk sky. Jupiter is the giant planet of the Solar System and despite its distance, is a bold and bright object for us to enjoy, especially in a telescope or binoculars.

Venus & Jupiter Conjunction

These two planets, like all of the objects in the Solar System, gradually change their position with respect to the background stars from day to day. All of the objects in the Solar System move along a common path across the sky, the Ecliptic. And from time to time these objects line up and create beautiful patterns and visually stunning sights.

On the morning of Monday August 18^th (from North America), we will see Venus and Jupiter in a conjunction, a close alignment of the two bodies from our Earthbound point of view. The two will be in the east just before sunrise, so you’ll have to get up early to see this, but it will be rewarding. The two will be less than the Moon’s width apart, and given their bright nature, the pairing should be spectacular. Through binoculars, you will also be able to see a lovely star cluster, the Beehive Cluster, in the background of stars, as Jupiter and Venus will be in the constellation Cancer and passing through the Beehive.

The image (courtesy of Sky & Telescope) shows where to look. From San Francisco, sunrise will be at 6:30 am and the Venus-Jupiter pair will rise at 5:00 am, so you will need a good northeastern horizon to see the pairing, and the 30 minute window starting at 5:00 will provide the best dark-sky viewing conditions as the glare of dawn will start to interfere by 5:30.

You can find an excellent write up on the conjunction on Sky & Telescope's website.